1. Comments to the SVD4 structure
8 June 2009
Toru Tsuboyama
Slides from M.Friedl, T.Bergauer, C. Irmler, P. Valentine, T. Tsuboyama

2. Sensor with slant layers
8 July 2009
T. Tsuboyama (KEK)

3. APV25 distribution
8 July 2009
T. Tsuboyama (KEK)

4. Sensors and APV chips Layer # Ladders Rect. Sensors [50μm] [75μm]
Wedge Sensors
APVs 6 17 68
850 5 14 42
560 4 10 20
300 3 8 16
192
Sum: 49
130 41
1902
Unit Cost:
2k€
400€
NRE Cost:
40k€
Total Cost:
72k€
300k€
122k€
761k€
Total:
1255k€
(1.7oku¥)
8 July 2009
T. Tsuboyama (KEK)

5. Comparison FADC cards SVD1 SVD2 SVD4 Ladders 8+10+14=32 6+12+18+18=54
=49
DSSD sensors
8*2+10*3+14*4=102
6*2+12*3+18*5+18*6=246
8*2+10*3+14*4+17*5=187
Hybrids
32*4=128
54*4=216
187
Readout chips
VA1 (128*5=640)
VA1TA (216*4=864)
APV25　(1902)
Number of hybrid cables
128
216
8*4+10*(4+1)+14*(4+2)+17*(4+3)=285 (Max)
Repeater
4+4=8 (DOCK)
5+5=10 (DOCK)
Not decided
Cooling
Dock+Endring
Dock+Endring+Ladder
FADC cards
32 (4 Hybrids1 FADC)
36 (24 VA1  1 FADC)
119 (16 APV25  1 FADC)
8 July 2009
T. Tsuboyama (KEK)

6. SVD1/SVD2 sensors were made from 4” wafers.
Why Number of sensors is smaller? Answer：Sensors are made from 6” wafer
SVD1/SVD2 sensors were made from 4” wafers.
8 July 2009
T. Tsuboyama (KEK)

7. Origami concept Chip-on-sensor concept for double-sided readout
Flex fan-out pieces wrapped to opposite side (hence “Origami“)
All chips aligned on one side  single cooling pipe
Side View (below)
8 July 2009
T. Tsuboyama (KEK)
26 June2009

8. Ladder shape (side view)
First sketch (to scale) of outermost ladder
Zylon rib
Cooling pipe
Nanonics connectors
Flex circuits
Cooling block (end ring)
8 July 2009
T. Tsuboyama (KEK)
26 June2009

9. Expanded view Rib Cooling tube APV25 chips
Flex for bottom side signal readout
Rohacel
DSSD
Normal hybrids
Kapton flex
Nanonics Connectors
Support parts
8 July 2009
T. Tsuboyama (KEK)
26 June2009

10. Disassembled Zylon rib APV25 chips (100µm=thin) Cooling pipe Rohacell
APV25 chips (300µm=thick)
TPG
Nanonics connectors
Flex circuits
T. Tsuboyama (KEK)
8 July 2009

11. Water tube not necessary in L3
T. Tsuboyama (KEK)
8 July 2009

12. Comments by S. Koike and N. Sato
I consulted KEK engineers, S. Koike and N. Sato, who designed and constructed SVD 1 and SVD 2 and asked their general idea of the SVD structure.
8 July 2009
T. Tsuboyama (KEK)

13. Ribs and cooling pipe
The combination of a Zylon rib and a cooling pipe is not appropriate for stable structure
Temperature dependence may be large
Precision of pipe-bending is not that good.
8 July 2009
T. Tsuboyama (KEK)

14. Two ribs Zylon is extremely strong in expansion.
Not strong to the bending force.
The following structure is weak in horizontal force
8 July 2009
T. Tsuboyama (KEK)

15. Two ribs + with roof With appropriate roof, structure will be stiff.
8 July 2009
T. Tsuboyama (KEK)

16. Is it possible to change ladder structure as follows?
The Rohacell layer makes the structure weak.
Roof (Zylon or CFRP)
Zylon rib
8 July 2009
T. Tsuboyama (KEK)

17. Ladder mount procedure
It must be difficult, if not impossible, to install the last ladder to the support structure.
SVD1 / SVD2  Only barrel type sensors.
SVD4  Slant sensor complicates the procedure
8 July 2009
T. Tsuboyama (KEK)

18. Solution
Ladder mount is done while support structure is divided to two halves.
After ladder mount is completed in left and right halves, they are put together around the beam pipe.
Ladder mount procedure becomes much easier.
How to keep precision between left-right and forward-backward support structure.
8 July 2009
T. Tsuboyama (KEK)

19. Summary Exchange of idea of the SVD structure has started.
Detail design is still far.
8 July 2009
T. Tsuboyama (KEK)